This invention relates to a method and an apparatus for processing color signals which convert color signals represented in a colorimetric system to signals represented in another colorimetric system and are usable in various color systems such as color television cameras, color image scanners, or color copying machines.
In some cases, the conversion of color signals in a first colorimetric system to color signals in a second colorimetric is performed for color correction or color adjustment. Such color signal conversion is realized by use of a ROM having a map or table in which sets of data of color signals in the second colorimetric system are stored in different storage locations designated in response to color signals in the first colorimetric system. In the ROM-based color signal conversion, a greater capacity is required of the ROM as the quantity of information represented by the color signals is increased. It is known to combine a color data interpolation technique with the ROM-based color signal conversion to reduce the required capacity of the ROM.
Japanese published examined patent application 52-16403, Japanese published examined patent application 56-14974, Japanese published examined patent application 58-16180, and Japanese published examined patent application 59-41227 disclose methods of processing color signals to execute color correction in color systems such as color image scanners or color facsimile machines. These prior art methods have some problems in accuracy of color correction and simplicity of associated machine structures.